The eggs and larvae of the New Zealand snapper Pagrus auratus are pelagic with early buoyancy provided by dilute body fluids. The swimbladder begins to develop on the third day after hatch from a dorsal evagination of the gut tube. Communication w1h the gut is lost on about the tenth day following pneumatic inflation at around day eight. At this age the gas gland system appears fully functional and capable of secreting gas. By the age of settlement at around 30 days the swimbladder is a fully functional replica of the adult form except for the lack of a resorbent capillary system which does not develop until later in juvenile life. The swimbladder of the adult is of the euphysoclist form with a dorsally located resorbent oval area and sits high in the pleural cavity. The ventral tunica externa is firmly attached to the connective tissue lining the pleural space. The adult swimbladder displaces 5.6% of the volume of the body and its volume is regulated to provide near neutral buoyancy. The connective tissue integument provides almost no restriction to volume changes brought about by vertical movements of the fish and the swimbladder obeys Boyle's Law for physiological pressure changes. The ability of the connective tissue of the tunica externa to accommodate large tissue strains is due to massive regular crimping of otherwise straight collagen fibrils allowing reversible extensions up to 130%. In all other respects however the tissue structure of the tunica externa is consistent with a tissue providing an active mechanical role. The fibrillar morphology and physicochemical properties of swimbladder collagen is consistent with the vertebrate type I form however there are interesting variations in collagen form distributed throughout the swimbladder. Fibrillar morphology of the highly extensible tunica interna is significantly different to that of the tunica externa and appears to play very little mechanical rote. The extensibilty of the tunica externa appears to be regulated by physiological stress and related to the past history of tissue strain.

The characterisation of the universal features of intertidal zonation on rocky coasts (Stephenson and Stephenson 1949; 1952; 1954; 1961) has stimulated many attempts t o explain the factors responsible for the observed patterns of distribution. Initial investigations which were essentially confined to the effects of a single factor upon different species suggested that ecological position was often correlated with physiological response. Recent studies have indicated that the subtidal distributions of algae show characteristic patterns (Kitching 1941 ; Bergquist 1960; Kain 1960; 1971; Morgans 1961 ; McLean 1962; Schwenke 1966; Neushul 1967; Clark and Neushul 1967; Larkum et al.1967; John 1971). However, there have been relatively few attempts to examine in detail and subsequently integrate the physiological response to environmental factors of major belt-demarcating algae of the sublittoral . The four New Zealand species of Carpophyllum are inhabitants of the uppermost sublittoral and the sublittoral fringe (Bergquist 1960; Dromgoole 1965). This particular study was undertaken in an attempt to elucidate the subtle differences in response which determine the distribution limits characteristic of each species. There is little information on the biology of Carpophyllum with the exception of some anatomical and embryological work (Delf 1939; Dawson 1940; Naylor 1954) and an earlier investigation of C. maschalocarpum (Dromgoole 1965). Thus to provide a basis for physiological experiments preliminary studies were directed to the following aspects: ( i ) a brief review of the morphology, anatomy and taxonomy of the genus, ( ii ) growth of sporelings in laboratory culture using various seawater media, ( iii ) definition of the geographical and vertical limits of the four species and a general study of their ecology with emphasis on population distributions, periodicitiy of reproduction and plant composition in relation to environment. The physiological response of algae to environmental factors has been examined by previous workers at the protoplasmic level using the criterion of resistance (e.g. Biebl 1956, 1962; Kanwisher 1957); at the metabolic level by measurement of photosynthesis and respiration (e.g. Chapman 1961n) ; and at the level of the whole plant by growth rates in laboratory cultures (e.g. Kain 1965) or of selected individuals in the field (e.g. Klugh and Martin, 1927). Attempts to culture Carpophyllum were not entirely successful. An earlier investigation indicated that the growth rates of Carpophyllum in situ are difficult to assess (Dromgoole 1965) and hence the metabolic approach, which does allow some integration of response to several factors by means of carbon balance calculations (e.g. Brown and Johnson 1964), has been used extensively in this study. The metabolic activity of large brown algae varies considerably with age and part of plant (Clendenning and Sargent 1957a, b; Chapman 1961a). To eliminate sampling problems in Carpophyllum a cuvette allowing continuous long-term monitoring of oxygen exchange of a single piece of material was developed. This laboratory apparatus has shown that the photosynthesis and respiration of the various organs is sensitive to environmental changes in pH, C02 supply, oxygen tension, light , water flow, dehydration and temperature. The nature and possible causes of the response t o each factor were examined in detail as this was considered essential to any interpretation of their ecological significance. Finally, the information obtained from these gas exchange measurements has been integrated by means of metabolic balance calculations and a descriptive synthesis of field and laboratory results has provided a general picture of the biology of these plants.

The scope of the present work is the systematic revision of the Demospongiae of the N.Z. region, here defined as including North and South Is. and all outlying islands as far north as Three Kings and South to Auckland and Cambell Is. The Kermadec Is. are not considered as part of the N.Z. region, but the sponges recorded from these islands are revised in the sytematic account. At present, 243 species of Demospongiae are recorded for this region, these belonging to 124 genera and 35 families. Of this total 49 species have been described as new and forty-six species are recorded as new to the fauna in this work.

The humpback whale was almost driven to extinction by commercial whaling in the Southern Ocean. Little is known about the degree of interchange among the remaining Southern Hemisphere populations. This thesis aimed to assess the connectivity among breeding grounds, feeding areas and migratory corridors of humpback whales using mitochondrial and nuclear DNA markers. The population structure of humpback whale populations in breeding grounds across the South Pacific and eastern Indian oceans was investigated, with an interest in the origins of whales in eastern Polynesia, using an extensive collection of mitochondrial DNA (mtDNA) sequences (n = 1,112; 470 base pairs in length). Samples were obtained from living whales at six breeding grounds: New Caledonia, Tonga, Cook Islands, French Polynesia (Society Islands), Colombia and western Australia. We found significant differentiation, at both the haplotype and nucleotide level, among the six breeding grounds (FST = 0.033; ΦST = 0.022) and for most pair-wise comparisons. The differentiation of the eastern Polynesia humpback whales is consistent with the hypothesis of a relic subpopulation, rather than vagrancy or colonization from known neighbouring breeding grounds. Regardless of their origin, it seems probable that islands of eastern Polynesia are now the primary breeding grounds for humpback whales feeding in the management Area VI (170°W – 120°W) of the Antarctic, as defined by the International Whaling Commission. A population of humpback whales migrates along the western South American coast, with breeding grounds mainly off Colombia and Ecuador and feeding areas off the western coast of the Antarctic Peninsula and in the channels and fjords ofsouthern Chile. We analysed the genetic relationship between humpback whales from these two summer feeding areas of the eastern South Pacific population to assess the potential heterogeneity in the migratory pattern of the population. We compared mitochondrial DNA control region sequences from 132 whales from the Antarctic Peninsula and 52 whales from the Magellan Strait areas. An AMOVA showed significant differences between the two feeding areas (FST = 0.180; ΦST = 0.169). A phylogenetic analysis showed both areas are represented in the AE clade that is only found in the Southern Hemisphere in the Colombian breeding ground. Genetic and previous demographic data (based on photo-identification) strongly suggest that both feeding areas are related to the same breeding ground but that heterogeneity exists among the feeding areas of this population, similar to that observed in the North Pacific and North Atlantic populations of humpback whales.Humpback whales migrating through eastern Australia and New Zealand have been linked with those breeding off northeastern Australia, New Caledonia, Fiji and Tonga, forming a single stock (Breeding Stock E). We investigated the relationship between the New Caledonian and Tongan breeding grounds, based on interchange of individual whales (genetically identified) and population genetic differentiation (mitochondrial DNA control region sequences and nuclear DNA microsatellites). We found significantly higher recapture probabilities within each breeding ground compared to the recapture probability between them using genetic identification, and significant differences at the population level in the FST and ΦST for mitochondrial and nuclear markers. These analyses suggest differentiation among the Breeding Stock E, supporting a proposed sub-stock division for New Caledonia (E2) and Tonga (E3). Historically, humpback whales off New Zealand coasts were caught during their migratory journeys between Antarctic feeding areas and tropical breeding grounds in the South Pacific. Here we investigated the genetic diversity of New Zealand humpback whales, comparing mitochondrial DNA control region sequence data with that from breeding grounds across the South Pacific (New Caledonia, Tonga, Cook Islands, French Polynesia and Colombia) and eastern Indian (western Australia) Oceans. We analyzed 30 samples collected around New Zealand, revealing 20 haplotypes. All haplotypes were found in New Caledonia and some were also found in other breeding grounds. New Zealand humpback whale haplotype diversity and nucleotide diversity were similar to those from the compared breeding grounds, but were significantly different at haplotype level from the Cook Islands, French Polynesia and Colombia breeding grounds. We found significant differences at haplotype level with the same three locations when a pair-wise AMOVA was performed. Three breeding grounds (western Australia, New Caledonia and Tonga) did not show significant differences at either nucleotide or haplotype levels. This genetic evidence and the available demographic data suggest a closer relationship of the New Zealand stock with New Caledonia and to a lesser extent with Tongan whales, supporting New Zealand as a primary migratory corridor for the humpback whales breeding in these western Pacific Islands.

This thesis examined the relative importance of natural and human influences to the population and assemblage dynamics of reef fishes in northeastern New Zealand. In particular, how different reef fishes responded to the implementation of no-take and partial marine reserve protection, and physical factors responsible for spatial differences in fish abundance. Included were data from prior to the establishment of a no-take marine reserve, multiple fished reference locations, biannual sampling and the use of two independent methods to provide quantitative estimates of fish abundance and size. This combination of factors is rare in studies of marine reserves was an important strategy leading to an improved understanding of the mechanisms structuring fish communities. Responses of the reef fish assemblage to changes in fishing mortality were examined at the Poor Knights Islands Marine Reserve. Full no-take marine reserve protection was implemented on the 1st Oct 1998 but for the prior 17 years, the Poor Knights Reserve comprised only two small no-take zones and allowed recreational fishing in the rest of the reserve. Following implementation of no-take marine reserve status the reef fish community changed rapidly; there were no obvious changes at either reference location. Species targeted by fishers, such as Pagrus auratus (snapper) and Caprodon longimanus (pink maomao), responded most strongly to protection. An increase in the density of some non-targeted species can probably be attributed to climatic effects, rather than a reduction in fishing pressure. A decline in the abundance of several species at the Poor Knights may have been a result of natural mortality, or competitive or predatory interactions with snapper. Along with human influences (fishing), physical variables are important in determining the distribution and abundance of reef fish. Four locations (two mainland and two island) were surveyed in northeastern New Zealand to determine spatial patterns for seven labrid species, one of the most abundant and widespread taxa of reef fish in New Zealand. The underlying mechanisms were then explored through an examination of the relationship between swimming ability (as examined through pectoral fin morphology), exposure and depth. Each of the four locations consistently displayed distinct labrid assemblages, likely due to the influence of the East Auckland Current. Regardless of location, there was a consistent depthrelated trend for most labrids and a trend for some species to be associated with certain levels of wave exposure. By analogy with tropical labrid assemblages, it was expected that there would be a clear relationship between pectoral fin aspect ratio and depth and/or exposure. However, this relationship was not strongly evident suggesting that wave exposure may not be as important for labrids on northeastern New Zealand reefs as hypothesised for tropical coral reef systems. The response of snapper, an important recreational and commercial finfish, was investigated following the cessation of all fishing at the Poor Knights. The rate of response of snapper to protection was rapid, in areas that had previously been partially protected as well as in those that had been fully protected from fishing, with the overall density of legal sized fish increasing by 7.4 times over 4 years, likely a result of recolonisation rather than recruitment. The 818% increase in snapper biomass has the potential to enhance areas outside or within the reserve through the export of biomass (eggs and/or larvae and adults) - the daily batch fecundity was 11 to 18 times higher at the Poor Knights compared to the reference locations. The effects of partial protection on reef fish were further examined at the Mimiwhangata Marine Park, an area where recreational fishing is permitted but all commercial fishing has been prohibited for 18 years. Snapper showed no difference in abundance or size between the Mimiwhangata Marine Park and adjacent control areas, with the density of snapper most similar to fished reference locations. The lack of any recovery by snapper within the Marine Park, despite the exclusion of commercial fishers and restrictions on recreational fishing, and results from the Poor Knights, indicates that partial fishing regulations are ineffective as conservation tools for protecting targeted species or for fish communities in general (i.e. through reduction in by-catch). Results from this study provide evidence that recreational fishing has significant impacts on reef fishes.

No description available.

No description available.

‘Infaunal haloes’ of either decreasing or increasing abundances of individual soft-sediment species with distance from reefs have been suggested to be caused by reef-associated predators. A large-scale mensurative experiment was used to investigate the distribution of two size classes of macrofauna with distance from the reef edge across three locations in northeastern New Zealand. The role of reef-associated predators, the snapper (Pagrus auratus Sparidae) and rock lobster (Jasus edwardsii Palinuridae), was investigated using established marine reserves at each location. Consistent patterns were found in a few large-bodied fauna. The hermit crab Pagurus novizelandiae occurred more frequently near the reef edge, whilst the heart urchin Echinocardium cordatum and bivalve Dosinia subrosea were more abundant further away from the reef. Dosinia subrosea and another bivalve, Myadora striata, exhibited lower biomass at sites with higher densities of snapper and rock lobster. In contrast, small-bodied macrofauna showed no consistent patterns with distance from the reef or among sites with different predator populations. It was hypothesised that predation was driving the distribution of large bivalves. An experiment was done to investigate this model using D. subrosea. Equal densities of this bivalve were established in plots either with or without cages at sites either inside or outside of reserves. Significant predation was detected, but only inside reserves. Much of this mortality could be specifically attributed to predation by large rock lobsters, given the distinctive marks on the valves of dead D. subrosea. Inside reserves, predators are not only more abundant but also larger. It was hypothesised that different size classes of predators would result in different levels of predation. Laboratory feeding experiments were used to investigate this model. Lobsters of all sizes chose D. subrosea over the heavier shelled D. anus. Small lobsters chose to prey on small D. subrosea and large lobsters more frequently chose larger prey. The distributions of these two bivalve species at protected (large predators) and fished sites (small predators) reflected the feeding choices observed in the laboratory. Results suggested that rock lobster populations are capable, where their size structure is not truncated by fishing pressure, of controlling population-level dynamics of bivalve communities adjacent to reefs.

‘Infaunal haloes’ of either decreasing or increasing abundances of individual soft-sediment species with distance from reefs have been suggested to be caused by reef-associated predators. A large-scale mensurative experiment was used to investigate the distribution of two size classes of macrofauna with distance from the reef edge across three locations in northeastern New Zealand. The role of reef-associated predators, the snapper (Pagrus auratus Sparidae) and rock lobster (Jasus edwardsii Palinuridae), was investigated using established marine reserves at each location. Consistent patterns were found in a few large-bodied fauna. The hermit crab Pagurus novizelandiae occurred more frequently near the reef edge, whilst the heart urchin Echinocardium cordatum and bivalve Dosinia subrosea were more abundant further away from the reef. Dosinia subrosea and another bivalve, Myadora striata, exhibited lower biomass at sites with higher densities of snapper and rock lobster. In contrast, small-bodied macrofauna showed no consistent patterns with distance from the reef or among sites with different predator populations. It was hypothesised that predation was driving the distribution of large bivalves. An experiment was done to investigate this model using D. subrosea. Equal densities of this bivalve were established in plots either with or without cages at sites either inside or outside of reserves. Significant predation was detected, but only inside reserves. Much of this mortality could be specifically attributed to predation by large rock lobsters, given the distinctive marks on the valves of dead D. subrosea. Inside reserves, predators are not only more abundant but also larger. It was hypothesised that different size classes of predators would result in different levels of predation. Laboratory feeding experiments were used to investigate this model. Lobsters of all sizes chose D. subrosea over the heavier shelled D. anus. Small lobsters chose to prey on small D. subrosea and large lobsters more frequently chose larger prey. The distributions of these two bivalve species at protected (large predators) and fished sites (small predators) reflected the feeding choices observed in the laboratory. Results suggested that rock lobster populations are capable, where their size structure is not truncated by fishing pressure, of controlling population-level dynamics of bivalve communities adjacent to reefs.

Content removed due to copyright restriction: Knapp M., Stockler K., Havell D., Delsuc F., Sebastiani F. & Lockhart P.J. (2005) Relaxed molecular clock provides evidence for long-distance dispersal of Nothofagus (southern beech). Plos biology 3(1), 38-43 / New Zealand has long been regarded as a key to understanding discontinuous distributions in the Southern Hemisphere. The archipelago is a fragment of the ancient super continent Gondwana. It has been isolated for 80 million years, has an excellent fossil record, and some of its most ancient biota such as the Southern Beeches (Nothofagus) and the Araucariaceae show disjunct distribution patterns with relatives on other fragments of Gondwana. Some of the most controversial problems of Southern Hemisphere biogeography with wide ranging implications involve New Zealand taxa. Three of them have been addressed in this thesis. The transoceanic relationships of the genus Nothofagus have long been regarded as an iconic example of a distribution pattern resulting from the break up of Gondwana. Phylogenetic analyses presented here show that, though most of the extant distribution of the genus is indeed shaped by tectonic events, Southern Beeches have crossed the Tasman Sea between Australia and New Zealand at least twice during the Tertiary period These results, together with findings of studies on other plant and animal taxa, emphasise the importance of dispersal but at the same time raise the question of whether any New Zealand taxa can be considered Gondwanan relicts. There is no geological evidence for the continuous existence of land throughout the Tertiary in the New Zealand area. However, molecular clock analyses presented in this thesis indicate that Agathis australis (New Zealand Kauri) diverged from its closest Australian relative prior to the Oligocene, or period of greatest submergence during the Tertiary. Thus these findings reject the hypothesis of the complete drowning of the New Zealand landmass during the Tertiary. They cannot reject the hypothesis of Stöckler et al. (2002) that the New Zealand Kauri lineage has persisted on the archipelago since its separation from Gondwana. Explanations for forest distribution patterns within the New Zealand islands themselves are diverse. New Zealand Nothofagus species show distribution gaps that are not explained by recent environmental factors alone. Early Miocene tectonic events and alternatively Pleistocene climates have been proposed as causes for this disjunct distribution pattern. Phylogeographic analyses reported in this thesis suggest that severe Pliocene and Pleistocene climates as well as Pliocene and Pleistocene tectonic events have shaped present day distribution and diversification of Nothofagus species in New Zealand.